tty-plain-v-not.py

#!/usr/bin/env python3

"""
usage: p.py

calling Python 'termios.tcsetattr' via 'tty.setraw' or 'tty.setcbreak'
wrongly changes the Type of 'mode[CC][VMIN]' and 'mode[CC][VTIME]'
to Int, from a Bytes of Length 1

diff'ing the 'termios.tcgetattr' shows this, at my macOS & at my Linux

bizarrely enough, calling 'termios.tcsetattr' to rollback all the 'mode'
spontaneously changes the Type of these two Items again,
back to a Bytes of Length 1 from an Int

Linux evidence @ https://gist.github.com/pelavarre/9883ab005ba1b5e0698aefcc4949acf7
macOS evidence @ https://gist.github.com/pelavarre/907b94cafe60728cfe4579f07d40688f
"""


import datetime as dt
import platform
import sys
import termios  # often '.so'
import tty  # often '.py'


print(dt.datetime.now())
print(platform.system())
print(termios.__file__)
print(tty.__file__)

fd = sys.stderr.fileno()
for func in (tty.setraw, tty.setcbreak):
    func_longname = "{}.{}".format(func.__module__, func.__name__)

    print()
    print()
    print(func_longname)

    a = termios.tcgetattr(fd)
    b = None
    try:
        func(fd)
        b = termios.tcgetattr(fd)
    finally:
        when = termios.TCSAFLUSH
        attributes = a
        termios.tcsetattr(fd, when, attributes)

    c = termios.tcgetattr(fd)
    assert str(a) == str(c), (a, c)

    print()
    print("Original vs {!r} samples of 'termios.tcgetattr'".format(func_longname))
    print()
    print(a)
    print()
    print(b)

    print()
    print("Differing Lists inside 'termios.tcgetattr'")
    for i, ipair in enumerate(zip(a, b)):
        (ai, bi) = ipair
        if not isinstance(ai, int):
            assert isinstance(ai, list), (ai,)

            print()
            print("[{}]".format(i))
            print(ai)
            print(bi)

    print()
    print("Differing Items inside 'termios.tcgetattr'")
    for i, ipair in enumerate(zip(a, b)):
        (ai, bi) = ipair
        if (type(ai) is not type(bi)) or (ai != bi):
            if isinstance(ai, int):
                print("[{}] from={} to={}".format(i, hex(ai), hex(bi)))
            else:
                for j, jp in enumerate(zip(ai, bi)):
                    (p, r) = jp
                    if (type(p) is not type(r)) or (p != r):
                        print("[{}, {}] from={} to={}".format(i, j, p, r))